A. Angoso

Preparation and characterization of a copper(II) compound with a new glycine Schiff base containing an ester function

SummaryA new Schiff base was obtained from glycine and ethyl-α-ketocyclopentylcarboxylate. This forms a potassium salt K(Rgly)·H2O, where Rgly=C10H14O4N. From this salt a new copper(II) complex was prepared, Cu(Rgly′)·2H2O, where Rgly′=C10H13O4N (deprotonated Schiff base). The compounds were characterized by i.r. spectroscopy, differential thermal analysis (d.t.a.) and thermogravimetric analysis (t.g.). The activation energy corresponding to the dehydration process for compounds was determined. On the basis of spectral data, the copper compound is believed to be pentacoordinate and square pyramidal.

Preparation and characterization of tetrachlorocobaltates of α,ω-alkanediammonium

Several tetrachlorocobaltates(II) of diprotonated α,ω-alkanediamines have been prepared using the following aliphatic diamines: NH2(CH2)nNH2, where n=2,3,5,6,7,8,9 and 10. Analytical results show that the compounds prepared correspond to the empirical formula (AAH2) [CoCl4], where AAH22+ is the doprotonated diamine. The formula for the compound with ethylenediamine is, however, (enH2)2CoCl6. Magnetic moments and electronic spectra confirm the existence of CoCl42− in all compounds.

Preparation and thermal study of the magnesium, calcium and barium compounds with a glycine Schiff base containing an ester function

Abstract The compounds N[Rgly]2·nH2O (M = Mg and Ca, n = 4; M = Ba, n = 2; Rgly− = C10H14NO4−), obtained by the condensation reaction between ethyl-α-ketocyclopentylcarboxylate and glycine in the presence of the metallic salt, were prepared and studied. The compounds were characterized by IR and UV spectroscopy, differential thermal analysis and thermogravimetric analysis.

Stabilization of Nickel(II) Chlorocomplexes with α,ω-Alkanediammonium Cations

Abstract The following nickel(II) chlorocomplexes stabilized with α,ω alkanediammonium cations were prepared: NiCl2·2bnH2Cl2·5H2O (1), 2NiCl2·2pnH2Cl2·4H2O (2), 2NiCl2·hnH2Cl2·4H2O (3), 2NiCl2·2hpH2Cl2·4H2O (4), where bn = 1,4-butanediamine, pn = 1,5-pentanediamine, hn = 1,6-xanediamine and hp = 1,7-heptanediamine. The solid state electronic spectra and magnetic moments show that nickel (II) is octahedral in all the compounds. The complex anion can be formulated as [Ni2Cl6(H2O)4]2− for compound (3), [Ni2Cl8(H2O)2]4- for compounds (2) and (4) and [NiCl4(H2O)2]2- for compound (1). By loss of water molecules the corresponding anhydrous compounds are produced; these apparently contain the dimer species with pentacoordinated nickel [Ni2Cl8]4-. The anhydrous compound obtained from (3) contains the polymeric species with hexacoordinated nickel [NiCl3]n- n.

Stabilization of cobalt(II) chloro-complexes with the butanediammonium cation

SummaryCobalt(II) chlorocomplexes with empirical formulae (bnH2)2CoCl6·2H2O (1) and (bnH2)2CoCl6 (2), where bnH22+ represents the diprotonated species of putrescine (1,4-butanediamine), were prepared.The visible spectra in the solid state and measurement of the magnetic moments permit the assignation of an octahedral geometry for cobalt in (1) and a tetrahedral geometry for (2).

Synthesis of New Alkanediamine Schiff Bases Containing an Ester Function. Preparation and Characterization of NiII Complex with 1,3-Trimethylenediamine Schiff Base

Abstract Schiff bases obtained by reaction between β-ketoester ethyl-α-ketocyclopentylcarboxylate (C8H12O3) and various aliphatic diamines NH2(CH2)nNH2, where n = 2, 3, 4, were prepared and studied. Also prepared was the complex of NiII and the Schiff base of 1,3-trimethylenediamine (L), with the formula NiLCl2-6H2O. The Schiff bases were characterized by elemental analysis, IR spectroscopy and 1H and 13C-NMR. The NiII compound was characterized by elemental analysis, IR, UV and visible spectroscopy, magnetic susceptibility and thermal analysis. A tetrahedral environment set N2Cl2 of donor atoms is proposed for NiII

Synthesis and Characterization of Germanium(IV) Complexes with α,ω-Alkanediamines

Abstract Germanium complexes of the general formula [M L2X2]X2 (M = Ge(IV); L= 1,7-heptamethylenediamine (hn), 1,8-octamethylenediamine (on), 1,9-nonamethylenediamine (nn), 1,10-decamethylenediamine (dn) and X= Br−) have been prepared and characterized by elemental analysis, molar conductance, i.r. spectroscopy, magnetic measurements and thermal techniques. A trans octahedral structure with -two bidentate diamine ligands as bridges and two bromide ligands has been assigned.

Tetraiodocobaltates of α,ω-Alkanediammonium: Preparation and Characterization

Abstract For the first time it has been possible to prepare Co(II) tetrabromocobaltates of empirical formula of (AAH2)[CoBr4 where AA is the diamine: 1,2-ethylenediamine(en), 1,3-triethylenediamine(tn), 1,4-tetramethylenediamine(bn), 1,5-pentamethylenediamine (pn), 1,6-hexamethylenediamine(hn), 1,7-heptamethylenediamine(hpn), 1,8-octamethylenediamine(on) and 1,9-nonamethylenediamine(nn). Paramagnetic susceptibilities and infrared and electronic spectra of the compounds were used to establish their stereochemistry. Racah parameters(B) and the splitting energy of the crystal field in Dq units have been calculated from the electronic spectra.

Preparation and study of 1,8-octamethylenediammonium chloronickelates

Abstract The compound (onH 2 )[Ni 2 Cl 6 (H 2 0) 2 ] ( I ), where on = 1,8-octamethylenediamine, is obtained as flat yellow crystals by reaction between nickel(II) chloride hexahydrate and the hydrochloride of the diamine. Dehydration of compound I leads to the reddish-yellow anhydrous compound (onH 2 )[NiCl 3 ]2 ( II ). Both compounds show diffuse reflectance spectra and magnetic moments typical of nickel(II) in an octahedral environment. The compounds were also studied by IR spectroscopy, differential thermal analysis and thermogravimetric analysis.

Synthesis and characterization of two derivatives of ethyl-α-ketocyclopentylcarboxylate with mercury(II)

Abstract The compounds HgC 8 H 12 Cl 2 O 3 and HgC 16 H 22 O 6 obtained by reaction between ethyl-α-ketocyclopentylcarboxylate and mercury(II) chloride and mercury(II) acetate, respectively, were prepared and studied. Both compounds were characterized by means of IR spectroscopy, differential thermal analysis and thermogravimetric analysis.